While the challenge had long been expected in party circules, councillors are bound by a code of secrecy around their internal party meetings, and can be disciplined for discussing events at Labour group meetings.

Cabinet positions are also being discussed at Monday’s meetings, although these will not be confirmed immediately. It is not clear whether or not Fahy will retain his cabinet position after challenging the leader.

Roberts’ 12 years in charge of Greenwich has seen the council embark on ambitious schemes such as the Ferrier Estate redevelopment in Kidbrooke and bringing Crossrail to Woolwich. Before he was leader, he was in charge of planning and regeneration when Greenwich was selected to be the home of the Millennium Dome.

But he has faced bitter criticism, not least from within his own party, for his style of leadership which has seen him impose tight discipline on his party’s councillors, while others complain the council has become remote from the people it is elected to serve.

His re-election as leader ensures he will be in charge of the council for the London Olympics, overseeing events in Greenwich Park, the Dome and the Royal Artillery Barracks.